The line graph illustrates the growth of citizens in Columbia, Yanhill and Washington from 1940 to 2000.
Overall, the population from all three different countries in the state of Oregon experienced a slight increase over the first half of the period and rose steeply on the next half.
In 1940, the number of citizens in Columbia was under 30 thousand and it increased to slightly above 30 thousand in 1970. Additionally, Yanhill had quite simillar growth for about 30 thousand and 45 thousand in 1940 and 1970 respectively. By the end of the period, in 2000 the amount of people living in Columbia was 60 thousand and for Yanhill was about 75 thousand.
In a contrary, Washington population in 1940 started for about 75 thousands. It went uphill to 120 thousand for the next period in 1970 and finally reached above 240 thousand at the end of 2000.
